/*
 * Copyright (c) 2022 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "ecmascript/js_regexp_iterator.h"

#include "ecmascript/builtins/builtins_regexp.h"
#include "ecmascript/object_fast_operator-inl.h"


namespace panda::ecmascript {
using BuiltinsBase = base::BuiltinsBase;
using BuiltinsRegExp = builtins::BuiltinsRegExp;
JSTaggedValue JSRegExpIterator::Next(EcmaRuntimeCallInfo *argv)
{
    ASSERT(argv);
    JSThread *thread = argv->GetThread();
    [[maybe_unused]] EcmaHandleScope handleScope(thread);

    // 1. Let O be the this value.
    JSHandle<JSTaggedValue> input(BuiltinsBase::GetThis(argv));
    // 2. If Type(O) is not Object, throw a TypeError exception.
    // 3. If O does not have all of the internal slots of a RegExp String Iterator Object Instance
    // (see 21.2.7.2), throw a TypeError exception.
    if (!input->IsJSRegExpIterator()) {
        THROW_TYPE_ERROR_AND_RETURN(thread, "this value is not a regExp iterator", JSTaggedValue::Exception());
    }

    JSHandle<JSTaggedValue> undefinedHandle(thread->GlobalConstants()->GetHandledUndefined());
    JSHandle<JSRegExpIterator> jsIterator = JSHandle<JSRegExpIterator>::Cast(input);
    // 4. If O.[[Done]] is true, then
    //     a. Return ! CreateIterResultObject(undefined, true).
    if (jsIterator->GetDone()) {
        return JSIterator::CreateIterResultObject(thread, undefinedHandle, true).GetTaggedValue();
    }

    // 5. Let R be O.[[IteratingRegExp]].
    // 6. Let S be O.[[IteratedString]].
    // 7. Let global be O.[[Global]].
    // 8. Let fullUnicode be O.[[Unicode]].
    JSHandle<JSTaggedValue> regexp(thread, jsIterator->GetIteratingRegExp(thread));
    JSHandle<JSTaggedValue> inputStr(thread, jsIterator->GetIteratedString(thread));
    bool global = jsIterator->GetGlobal();
    bool fullUnicode = jsIterator->GetUnicode();

    // 9. Let match be ? RegExpExec(R, S).
    JSMutableHandle<JSTaggedValue> match(thread, JSTaggedValue::Undefined());
    bool isFastPath = BuiltinsRegExp::IsFastRegExp(thread, regexp.GetTaggedValue());
    if (isFastPath) {
        match.Update(BuiltinsRegExp::RegExpBuiltinExec(thread, regexp, inputStr, isFastPath, true));
    } else {
        match.Update(BuiltinsRegExp::RegExpExec(thread, regexp, inputStr, false));
    }
    RETURN_EXCEPTION_IF_ABRUPT_COMPLETION(thread);

    // 10. If match is null, then
    //     a. Set O.[[Done]] to true.
    //     b. Return ! CreateIterResultObject(undefined, true).
    // Else,
    if (match->IsNull()) {
        jsIterator->SetDone(true);
        return JSIterator::CreateIterResultObject(thread, undefinedHandle, true).GetTaggedValue();
    }
    if (!global) {
        //  b. Else, if non global case
        //    i. Set O.[[Done]] to true.
        //    ii. Return ! CreateIterResultObject(match, false).
        jsIterator->SetDone(true);
        return JSIterator::CreateIterResultObject(thread, match, false).GetTaggedValue();
    }
    // a. If global is true, then
    //    i. Let matchStr be ? ToString(? Get(match, "0")).
    const GlobalEnvConstants *globalConstants = thread->GlobalConstants();
    JSHandle<JSTaggedValue> zeroString(globalConstants->GetHandledZeroString());
    JSHandle<JSTaggedValue> getZero(JSObject::GetProperty(thread, match, zeroString).GetValue());
    JSHandle<EcmaString> matchStr = JSTaggedValue::ToString(thread, getZero);
    RETURN_EXCEPTION_IF_ABRUPT_COMPLETION(thread);
    // ii. If matchStr is the empty String, then
    //     1. Let thisIndex be ? ToLength(? Get(R, "lastIndex")).
    //     2. Let nextIndex be ! AdvanceStringIndex(S, thisIndex, fullUnicode).
    //     3. Perform ? Set(R, "lastIndex", 𝔽(nextIndex), true).
    if (EcmaStringAccessor(matchStr).GetLength() == 0) {
        uint32_t lastIndex = static_cast<uint32_t>(BuiltinsRegExp::GetLastIndex(thread, regexp, isFastPath));
        RETURN_EXCEPTION_IF_ABRUPT_COMPLETION(thread);
        uint32_t nextIndex = static_cast<uint32_t>(
            BuiltinsRegExp::AdvanceStringIndex(thread, inputStr, lastIndex, fullUnicode));
        BuiltinsRegExp::SetLastIndex(thread, regexp, JSTaggedValue(nextIndex), isFastPath);
        RETURN_EXCEPTION_IF_ABRUPT_COMPLETION(thread);
    }
    // iii. Return ! CreateIterResultObject(match, false).
    return JSIterator::CreateIterResultObject(thread, match, false).GetTaggedValue();
}

JSHandle<JSTaggedValue> JSRegExpIterator::CreateRegExpStringIterator(JSThread *thread,
                                                                     const JSHandle<JSTaggedValue> &matcher,
                                                                     const JSHandle<EcmaString> &inputStr,
                                                                     bool global, bool fullUnicode)
{
    ObjectFactory *factory = thread->GetEcmaVM()->GetFactory();
    if (!matcher->IsJSRegExp()) {
        JSHandle<JSTaggedValue> undefinedHandle(thread->GlobalConstants()->GetHandledUndefined());
        THROW_TYPE_ERROR_AND_RETURN(thread, "matcher is not JSRegExp", undefinedHandle);
    }
    JSHandle<JSTaggedValue> iter(factory->NewJSRegExpIterator(matcher, inputStr, global, fullUnicode));
    return iter;
}
}  // namespace panda::ecmascript